The answer is "opportunity cost". But who really believes in that?
I call it the batman fallacy. Many people (young men in particular) say to themselves "if I was more disciplined, I could dedicate my whole life to martial arts (or programming, or art, or w/e) and become batman (or John Carmack, or Van Gogh)". But it's not true, of course.
And it's the same with many managers. "Instead of spending x% on task A and y% on task B, why dont you spend (x-z)% on A and (y+z)% on B?" It's absurd.
Brute attempts to capture opportunity costs are doomed to fail. You squeeze one end (block youtube shorts) and it comes out the other (eg you argue with coworker). It's really much easier to stop punishing yourself for lost time and find happiness in who and where you are.